Electric Power ›› 2022, Vol. 55 ›› Issue (12): 112-123.DOI: 10.11930/j.issn.1004-9649.202209119

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Space Charge Behavior and Mechanism of Polyimide Under Pulse Voltage

HOU Jianjian1, WANG Chanjuan1, GUO Haoxin2, CHEN Chen1, LIU Xuemin3, HE Dongxin2   

  1. 1. State Grid Shandong Guangrao Power Supply Company, Dongying 257300, China;
    2. Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment, School of Electrical Engineering, Shandong University, Jinan 250061, China;
    3. State Grid Shandong Dongying Power Supply Company, Dongying 257000, China
  • Received:2022-09-30 Revised:2022-11-07 Published:2022-12-28
  • Supported by:
    This work is supported by the National Natural Science Foundation of China (No.51907105).

Abstract: The insulation of power electronic equipment is more likely to deteriorate and fail early because it is operated with high repetition rate and steep rise time pulse voltage for a long time. In order to explore the microscopic mechanism of insulation failure under pulse voltage, the space charge distribution before and after the pulse edge at the nanosecond level was studied and compared, and the influences of electric field strength and silicone oil on the charge vibration waveform at the pulse edge were explored. Based on an analysis of the spectrum of charge vibration waveform and voltage waveform and the charge accumulation characteristics at different pulse rise times, the charge vibration mechanism at the time of pulse voltage edge and the influence mechanism of charge behavior on insulation degradation under nanosecond pulse were expounded. It was found that the charge distribution characteristics before and after the rising edge and falling edge of the nanosecond pulse were different, and a special space charge migration behavior was found at the pulse edge; the electric field strength would affect the accumulation speed and amount of the heteropolar charge, thereby affecting the shape of charge vibration waveform; the application of silicone oil between the electrode and the sample would affect the polarity of the charge vibration waveform; the voltage component in the 5×106~1×107 Hz frequency band played a major role in the space charge vibration; the charge accumulation under the nanosecond pulse voltage caused serious electric field distortion.

Key words: pulse voltage, polyimide, electric field strength, silicone oil, charge vibration waveform, charge accumulation